Reviews & Analysis

Some studies have reported reduced secretion of glucagon-like peptide-1 (GLP-1) in patients with type 2 diabetes mellitus; however, other studies have failed to find such an association. The evidence for, and against, reduced GLP-1 secretion in the etiology of type 2 diabetes mellitus is debated by the authors of this Viewpoint.

Since a 'type 2 phenotype' has become increasingly common in patients with type 1 diabetes, the etiology of diabetes can no longer be established exclusively on the basis of phenotypic presentation. This Case Study illustrates the difficulty of diagnosis in an obese adolescent with new onset diabetes, and discusses management and follow-up strategies.

Cushing disease is an uncommon disorder frequently caused by microadenoma. Although treatment has been greatly improved by the evolution of radiotherapy, radiosurgery and medications, in a substantial proportion of cases the disease is refractory or recurrent. This Review presents and discusses the various management options for such patients.

Thiazolidinediones are antihyperglycemic drugs used to treat diabetes that increase insulin sensitivity in adipose tissue, muscles and the liver to increase glucose use and decrease its production. They are known, however, to also affect bone. This Review examines the available data to assess the effect of these drugs on skeletal health.

Alterations in the hypothalamic–pituitary–adrenal axis play an important part in survival of critically ill patients. The usefulness of currently available therapeutic interventions designed to correct these alterations is, however, unclear. This Review explains the response to stress in critically ill patients and discusses issues surrounding terminology and the role of glucocorticoids in therapy.

The global obesity epidemic shows no sign of slowing down. Primary prevention at the population level is a huge challenge, however, particularly given the sedentary lifestyle of many modern societies. Nonetheless, the authors of this Viewpoint argue that targeting physical inactivity could represent a step in the right direction.

Subclinical hyperthyroidism is a common biochemical finding, characterized by low levels of serum TSH but normal serum T₄ and T₃levels. Potential adverse consequences include increased risk of atrial fibrillation and death from vascular diseases. Whether the evidence for harm associated with subclinical hyperthyroidism is sufficient to drive the need for treatment is discussed.

In 1988, Barbara Sherwin reported that surgical menopause was associated with a marked decline in verbal memory and that treatment with estradiol immediately after surgery prevented this deficit. The author of this Viewpoint describes how our understanding of estrogen and neurocognitive function has evolved in the 20 years since that seminal report.

Some patients with Turner syndrome have a karyotype showing mosaicism. This article describes the case of a boy with 45,X0/46,XY mosaicism, often referred to as mixed gonadal dysgenesis, who was evaluated for short stature. Different types of Turner syndrome mosaicism and their associated phenotypes, as well as the management of short stature in these patients, are discussed.

Autoimmune thyroiditis, which manifests as Hashimoto thyroiditis and Graves disease among other forms, is an inflammatory disorder of the thyroid gland. Various environmental factors interact with susceptibility genes and seem to be associated with disease initiation and to influence duration and severity. This Review summarizes the currently available information and highlights the areas that urgently require further study.

Between 20% and 40% of patients with diabetes ultimately develop nephropathy. The bank of data on the multiple and complex mechanisms, disease markers and disease progression continues to grow. This article provides an overview of the current status of findings relating to underlying mechanisms and genetic susceptibility.

Transfer of adolescents from pediatric care to adult endocrinology services represents a major medical issue. Unfortunately, however, many factors prevent effective transition. The authors of this Viewpoint discuss possible strategies—such as the creation of dedicated transition clinics—that might be implemented to ensure smooth transition to adult care.

Thyroid stimulation in Graves disease is caused by antibodies to the TSH receptor that have thyroid-stimulating or thyroid-blocking activity. Antibody detection can aid diagnosis and prediction of outcomes of the disease, as well as prediction of the course of associated ophthalmology. In this Review, Ajjan and Weetman describe the different measurement techniques available and their clinical applications.

Management of diabetes mellitus is occasionally confounded by lack of understanding on the part of physicians and patients of issues surrounding the risks and benefits of antidiabetic drugs. The need for adequately powered outcome studies that minimize the effects of the unknown on prescribing habits in diabetes care is debated.

Struma ovarii is a rare tumor, characterized by the presence of thyroid tissue in an ovarian teratoma. In this article Yassa et al. describe a patient who presented to her gynecologist with a pelvic mass, which was found to be a malignant struma ovarii. The investigations and treatment options for this tumor are described.

Age-related declines in dehydroepiandrosterone sulfate concentration parallel the physical and cognitive changes of aging. This observation suggests that these events are causally related and that replacement therapy might have beneficial effects in the elderly. The authors of this Viewpoint consider the evidence for, and against, such an approach.

Various endocrine abnormalities arise in anorexia nervosa. Most are related to the body's adaptation to starvation, but some might relate to susceptibility to recurrence, as they persist after recovery. Lawson and Klibanski summarize the main endocrine alterations in girls and women, concentrating particularly on bone loss.

Identification and subsequent treatment of individuals with prediabetes can prevent progression to type 2 diabetes mellitus. Although lifestyle changes are critical in this setting, the question of whether pharmacotherapy should also be used remains unanswered. The authors of this Viewpoint, therefore, discuss potential strategies for pharmacologic intervention.

Obesity can be a cause of secondary hypogonadism. This article describes a male patient with infertility in the setting of obesity, who was successfully treated with the aromatase inhibitor anastrozole. The authors illustrate the connections between adiposity, aromatase expression, testosterone and estradiol levels, and the suppression of gonadotropin release and spermatogenesis.

The thyroid gland and thyroid hormones have important roles in fertility and throughout pregnancy. In fertile and infertile women with thyroid disorders, such as hypothyroidism or thyroid autoimmunity, therapy might enable conception, but a host of problems can arise. Poppe et al. present an overview of the interactions between thyroid disorders and spontaneous and assisted pregnancies.